Inboard-outboard marine drives



Oct. 8, 1968 cHAMBERLAm 3,404,656

INBOARD-OUTBOARD MARINE DRIVES Filed Aug. 22, 1966 2 SheetsSheet 1 Oct. 1968 A. H. CHAMBERLAIN INBOARD'OUTBOARD MARINE DRIVES 2 Sheets-Sheet 2 Filed Aug. 22, 1966 United States Patent 3,404,656 INBOARD-OUTBOARD MARINE DRIVES Allan Hawker Chamberlain, 64 Irving Road, Toorak, Victoria, Australia Filed Aug. 22, 1966, Ser. No. 574,084 Claims priority, application Australia, Aug. 23, 1965, 63,068/ 65 6 Claims. (Cl. 115-41) ABSTRACT OF THE DISCLOSURE The present invention relates to an inboard-outboard drive unit comprising a mounting member for attachment to the stern of a water-born craft, in which a gimbal member is supported by the mounting member for angular movement about a horizontal transverse axis, in which the drive unit is provided with a drive housing having an upper coupling connecting the drive housing to the gimbal member for angular movement about a substantially vertical axis and about a horizontal axis disposed above the horizontal axis of said gimbal member and a lower coupling is provided connecting the drive housing to the gimbal member for angular movement about a vertical axis of the upper coupling and in which said lower coupling is releasable to permit inversion of the drive housing about the horizontal housing of the upper coupling.

This invention relates to inboard-outboard drive units for the propelling of ski-boats, launches and the like to be mounted on the transom of a craft and drive coupled through the transom to a motor mounted within the craft.

This type of drive unit is becoming increasingly popular due to the convenience in assembly, consequent upon the permanent location of the motor unit in the craft, leaving only the drive unit outboard, a further appeal being the fuel economy in comparison with the conventional outboard motor.

It is essential in such inboard-outboard drive units to provide an effective coupling and transom mounting which facilitate relative angular movements about a horizontal axis for obstacle clearing in the water, or to assume an idle or tilted parked position when moored, beaching, or during trailer transport of the craft. It is also essential that such coupling and transom mounting allow the drive unit to swivel around a substantially vertical pivot to provide for steering the craft.

The coupling between the motor and the drive unit usually includes a gimbal or like construction with pivots in substantially horizontal and vertical planes and suitable constant velocity type universal joints to couple the drive shafts of the motor and drive unit. Provision is made to decouple the shafts for removal of the drive unit.

Whilst the outboard-inboard drive units at present in use provide for an effective obstacle clearing and tilting movement, the extent of the movementwhilst generally satisfactory for obstacle clearing-is generally insufficient to clear the lower portion of the drive unit including the propeller from the water when the craft is moored. As the craft may be moored over long periods during a season, continuous or frequent immersion of portion of the drive unit in the water may set up corrosion or deterioration of the metal, and also permits the accumulation of marine incrustation. Incidentally, in the tilted or parked position, the drive unit is not readily accessible from within the craft for maintenance and the propeller cannot be readily reached to clear weeds or ropes Withwhich it may be fouled, or for maintenance purposes.

Another serious fault in present drive units is related to the flexible covering or concertina bellow surrounding and protecting the universal jointed drive for coupling to the motor. When the unit is left for long periods in tl parked position, the rubber or similar flexible materi. in the concertina bellows is distorted with the lower part i tension. Materials of the types used assume this distorte shape as their free form and when the unit is released fro] the parked position and upon resuming the drive positic the distorted concertina bellows buckles inwards, often 1 a position where it rubs against the universal joints and worn through. Problems are also encountered through tl tendency of the concertina bellows material to crack 1 areas where it is held in tension for long periods.

Now this invention has for its principal objective tl provision of a simple elfective inboard-outboard drive un that permits independent relative angular movement tilting at will to such an inclination that, in the idle r parked position, said entire drive unit is disposed we above water level and, in this fully tilted position, the co] certina bellows are not distorted. In this position, propellr and drive elements are also accessible for maintenanr operations from within the craft. Moreover, the propelll drive unit in the fully tilted position is conveniently locate to be grasped from an inboard position, detached from tl coupling unit and lifted into the craft.

The above objectives are accomplished WlthOl sacrificing the desirable features achieved by permittir the unit to tilt around the normal horizontal gimbal pil and without disconnecting the drive when an obstructic is encountered by the drive unit while the craft is 1' motion.

With that objective in view, there is provided .accordir to this invention an inboard-outboard drive unit compri ing a mounting member for attachment tothe stern of craft, a gimbal member supported by the mounting men her for angular movement relative thereto about a tran verse horizontal pivot axis, a drive housing, an uppr coupling connecting the drive housing to the gimbal men her for angular movement relative thereto about a sul stantially vertical axis and also about a horizontal ax which is disposed above the horizontal pivot axis of ti gimbal member, and a lower coupling connecting the dl'l\ housing to the gimbal member for angular movement rel: tive thereto about a vertical axis coaxial with the vertic. axis of the upper coupling, said lower coupling beir releasable to permit inversion of the drive housing abol the horizontal axis of the upper coupling.

In particular, the inboard-outboard drive unit comprisr a mounting member for attachment to the stern of a boa an annular shaped gimbal member to the mounting men her for angular movement relative thereto about a ho izontal axis transverse to the axis of the craft, upper an lower coupling members pivotally connected to the gimb: member for angular movement relative thereto about common substantially vertical axis, said upper and lows coupling members being disposed respectively above an below the horizontal pivot axis of the gimbal member, an a drive housing detachably connected to said couplin members for movement in unison therewith about sai substantially vertical axis, the connection between the u] per coupling member and the drive housing comprising horizontally disposed pin extending through an elongate slot in the drive housing and attached at each end to tt upper coupling member, whereby the drive housing ma angularly move about said pin and slide relative to the pi in a direction normal to the pin axis, said pin bein adapted to permit clamping of the drive housing to tl: upper coupling member to prevent relative movemer therebetween, the connection between the lower couplin member and the drive housing including clamp meat normally restraining the drive housing against movemel relative to the upper and lower coupling members an releasable to permit angular movement of the drive hous ing about the pin of the upper connection from a downwardly projecting drive position to an inverted park position.

The drive housing includes a propeller shaft j'ournalled in the lower portion of the drive housing, an input shaft journalled in the upper portion of the drive housing, a constant velocity universal joint fixed at one end to the input shaft and projecting forwardly from the housing for releasable drive coupling at the other end to an output shaft of a power unit, a tubular cover made of flexible resilient material surrounding the universal joint and sealably connected at one end to the drive housing concentric with the input shaft, a rigid flange sealably connected to the other end of the tubular cover, an annular sealing member mounted in the flange and engaging said other end of the universal joint to maintain said other end coaxial with the input shaft of the drive housing when disengaged from the output shaft of the drive housing, and means to releasably clamp the flange in sealed relation to the mounting member when the universal joint is coupled to the output shaft of the power unit.

When the craft is moored, the drive housing is disconnected from the lower coupling and is then free to describe angular movements about the horizontal pivot connection provided by the upper coupling. This may be achieved by a cable attached to the drive housing and connected to a winch mounted near the stern of the craft. This same winch may be used to raise the drive housing around the usual horizontal gimbal pivot.

The drive housing when swung to the inverted position, in which it may be inwardly inclined beyond the vertical toward the craft, is conveniently accessible by a person standing in the craft for cleaning, changing or adjusting the propeller. Upon release of the upper coupling, the user may conveniently lift the drive housing into the craft.

The invention will be more readily understood fro-m the following description of one practical arrangement of the inboard-outboard drive unit as illustrated in the accompanying drawings in which:

FIGURE 1 shows the stern of a craft with an inboard motor complete with the outboard drive unit in the straight-ahead position.

FIGURE 2 shows the drive unit deflected to clear an obstruction.

FIGURE 3 shows how the drive unit is movable rearwards to free it from the lower suspension means and splined drive shaft prior to the unit being swung out of the water.

FIGURE 4 illustrates the facility with which the drive unit can be swung completely over the transom of the craft when moored or for cleaning or overhauling the unit in this position being conveniently located for complete removal from its mounting and lifted into the craft for storage.

FIGURE 5 shows in more detail the parts associated with the steering, coupling and drive mechanism; and

FIGURE 6 is a sectional plan view showing the coupling arrangement and the means to protect its parts from moisture.

In the arrangement shown in FIGURES 1 to 4, the craft 1 is powered by multi cylinder engine 2 having a gear box 3, the output shaft 4 of which passe through the transom 5 and is provided with a universal coupling 6 transmitting drive to the system of bevel gears 7, 7a and the shaft 8. The lower end of the shaft carries a bevel gear wheel 9 meshing with a complementary bevel gear wheel 9 meshing with a complementary bevel gear wheel 10 on the end of the propeller shaft 11 on which is mounted the propeller 12.

The parts;6 to 12 form the propeller drive and are aoused in or mounted to the drive housing 13 which is lertically mounted on slightly forwardly inclined vertical axis 14 for steering purposes, the axis passing through the aligned pivotal points of an angular gimbal ring 15.

In the arrangement shown, the gimbal ring 15 pivotally fit supports at two spaced vertical points two rearwardly projecting coupling arms 16, 17, the ends of the arms being bifurcated to receive the drive housing, threaded pins 20, 21 projecting laterally from the drive housing 13 to normally seat in notches 18 and 19 of the bifurcated rear ends of the arms. The pin in the upper arm 16 extends through the elongated slot 22 in the upper end of the drive housing to permit sliding of the drive housing rearwardly to disconnect the drive shaft from the motor. The arms 16 and 17 are pivotally mounted on the gimbal ring 15 at 16a and 17a about the common axis 14 as shown more clearly in FIGURE 5.

The threaded pins 20, 21 and the coupling arms 16, 17 are arranged so that, when the pins are seated in the respective notches 18, 19 with the pin 20 at the rear of the slot 22, the drive housing is in the coupled position with the drive shaft of the motor. Upon tightening nuts onto the ends of the pins, the drive housing is secured in the operative position, whereupon it will function in the normal manner in which the gimball ring 15 pivots relating to the mounting member 30 about a pair of pins 15a having a common horizontal axis when the drive unit strikes an obstacle in the water, or is normally tilted as shown in FIGURE 2.

The drive housing may be decoupled from the drive shaft 4 and swung into a position completely out of the water as shown in FIGURE 4 when it is intended to moor the craft for any length of time or when it is desired to clean or service the propeller or underwater parts.

To effect this operation, the nuts on the pins 20 and 21 are slackened off whereupon the drive housing 13 may be moved rearwardly a distance indicated at X in FIG- URE 3, in which position the pins 21 are released from the lower coupling arms 17, 19 and the upper pins 20 slide to the front end of the cooperating slot 22 in the housing 13.

The drive housing may be then swung upwardly upon and about the horizontal transverse axis formed by the pins 20, and to assist in this movement a small hand or power operated winch 23 is provided with a flexible cable 24, the free end of which is detachably fixed to a pin 25 on the rear of the drive housing 13. The drive housing is thus positioned completely out of the water and as shown in FIGURE 4 rests in an inverted position against the transom with the propeller and normal underwater parts presented to the operator for servicing from within the hull of the craft. Should it be necessary to remove the drive housing for storage or a major overhaul, the nuts on the upper pins 20 are removed and by tilting the unit upon the edge of the transom the pins are caused to move out of the notches 18 in the upper coupling arm 16, thereby leaving the unit free for man-handling into the hull of the craft.

In normal use, the universal coupling 6 shown more clearly in FIGURE 6 maintains its driving connection with the motor drive shaft 4 by reason of a splined section 4a and quite substantial tilting of the drive housing 13 upon striking an obstruction causes the interengaging splined parts merely to move upon each other without separation. The coupling, splined parts and associated bearings are protected from water by a flexible concertina-bellows like shroud or boot 26 made of rubber or other suitable flexible resilient material reinforced by a helically wound wire core 27. One end of the shroud is secured in sealed relation to the housing 13 by a clamping ring 26a, the other end being similarly attached by a ring 26b to the flange 28 adapted to be clamped by screws 29 against the mounting member 30 supporting the gimbal ring 15 on the transom 5. When removing the drive housing 13 from the craft, the screws 29 are retracted freeing the flange 28 which is withdrawn through the gimbal ring as the unit is tilted about the pins 20, the splined section of the coupling 6 sliding off the shaft 4. The flange 28 carries the seal 28a which co-operates with the splined end of the universal joint and the flange 6a thereon to centralise the splined end when disengaged from the shaft 4 so that, when reassembling the drive unit, no difficulty is experienced in aligning the two splined parts as they approach each other. The tension in the shroud 26 assists in this centralising action and holds the seal 28a against the flange 6a when the drive housing is removed to prevent the entry of foreign matter.

To eliminate excessive rear weight and overhang, the main mounting member 30 has an annular recessed portion 31 into which the upper part of the gimbal ring moves when the drive housing is tilted upon meeting an obstruction.

The most advantageous line of thrust for the propeller is obtained by experimentation, the adjustment being obtained by varying the angle of the drive housing 13 upon the gimbal pivot pins 15a. Once the correct angle has been attained, the downward swinging movement of the drive housing 13 may be arrested by inserting a bolt or stud in selected holes 32 in side webs 33 of the main mounting member 30, the lower part of the gimbal ring abutting against the bolt in the hole as shown in FIG- URE;5.

Shock absorbers, one of which is shown at 34 are provided between the gimbal ring and a convenient part of the mounting member 30 to control the action of the movable parts of the mechanism, the disposition of the shock absorbers being such that they are maintained above the water line and out of reach of incrustation.

An important advantage arising from the use of the present means of support for the drive housing is that the rubber cover or boot encasing the universal joint remains straight when the drive housing is swung up to the mooring position, and there is no tendency to become distorted or cracked as frequently occurs with the covers or boots which is subjected to bending for long periods When the drive housing is tilted.

Provision is made for instance in the form of a detachable plug to be inserted in the opening 3a (FIGURE 6), to seal the gear box and prevent ingress of water upon disconnection of the coupling 6. The bifurcated ends of the suspension arms permit the limited bodily movement of the propeller drive unit to decouple the drive shafts preparatory to the independent movement of the drive housing to the parked or mooring positions.

I claim:

1. An inboard-outboard drive unit comprising a mounting member for attachment to the stern of a craft, a gimbal member supported by the mounting member for angular movement relative thereto about a transverse horizontal pivot, a drive housing, an upper coupling connecting the drive housing to the gimbal member for angular movement relative thereto about a substantially vertical axis and also about a horizontal axis which is disposed above the axis of said horizontal pivot of the gimbal member, and a lower coupling connecting the drive housing to the gimbal member for angular movement relative thereto about a vertical axis coaxial with the vertical axis of the upper coupling, said lower coupling being releasable to permit inversion of the drive housing about said horizontal axis of said upper coupling.

2. An inboard-outboard drive unit as claimed in claim 1, wherein the upper coupling is releasable to permit sliding movement of the drive housing relative thereto in a direction normal to the horizontal axis of the upper coupling away from the gimbal member.

3. An inboard-outboard drive unit as claimed in claim 1, wherein the drive housing is disconnectable from the upper coupling after release of the lower coupling to permit complete removal of the drive housing from the gimbal member.

4. An inboard-outboard drive unit comprising a mounting member for attachment to the stern of a boat, an annular shaped gimbal member, pivot pins supportably connecting the gimbal member to the mounting member for angular movement relative thereto about a horizontal axis transverse to the axis of the craft, upper and lower coupling members pivotally connected to the gimbal member for angular movement relative thereto about a common substantially vertical axis, said upper and lower coupling members being disposed respectively above and below the horizontal pivot axis of the gimbal member, and a drive housing detachably connected to said coupling members for movement in unison therewith about said substantially vertical axis, the connection between the upper coupling member and the drive housing comprising a horizontally disposed pin extending through an elongated slot in the drive housing and attached at each end to the upper coupling member, whereby the drive housing may angularly move about said pin and slidee relative to the pin in a direction normal to the pin axis, said pin being adapted to permit clamping of the drive housing to the upper coupling member to prevent relative movement therebetween, the connection between the lower coupling member and the drive housing including clamp means normally restraining the drive housing against movement relative to the upper and lower coupling members and releasable to permit angular movement of the drive housing about the pin of the upper connection from a downwardly projecting drive position to an inverted park position.

5. An inboard-outboard drive unit as claimed in claim 4, including a propeller shaft journalled in the lower portion of the drive housing, an input shaft journalled in the upper portion of the drive housing, a constant velocity universal joint fixed at one end of the input shaft and projecting forwardly from the housing for releasable drive coupling at the other end to an output shaft of a power unit, a tubular cover made of flexible resilient material surrounding the universal joint and sealably connected at one end to the drive housing concentric with the input shaft, a rigid flange sealably connected to the other end of the tubular cover, an annular sealing member mounted in the flange and engaging said other end of the universal joint to maintain said other end coaxial with the input shaft of the drive housing when disengaged from the output shaft of the drive housing, and means to releasably clamp the flange in sealed relation to the mounting member when the universal joint is coupled to the output shaft of the power unit.

6. An inboard-outboard drive unit as claimed in claim 1, including a propeller shaft journalled on the lower portion of the drive housing, an input shaft journalled in the upper portion of the drive housing, transmission means drivingly coupling input and propeller shafts, a constant velocity universal joint coupled to the input shaft and projecting forwardly therefrom through the gimbal member to drivingly engage a. power unit output shaft, a tubular cover of flexible resilient material surrounding the universal joint and sealably connected at one end to the drive hous ng concentric w.'th the input shaft, a rigid flange sealably connected to the other end of the tubular cover, an annular sealing member mounted in the flange and engaging said other end of the universal joint to maintain said other end coaxial with the input shaft of the drive housing when disengaged from the output shaft of the drive housing, and means releasably clamping the flange in sealed relation to the mounting member when the universal joint is coupled to the output shaft of the power unit.

References Cited UNITED STATES PATENTS 1,845,712 2/1932 Jacques --41 2,473,618 6/ 1949 Stillwagon 64-32 2,922,388 1/1960 Smith 115-41 3,136,287 6/1964 North 11541 3,181,494 5/1965 Kiekhaefer et a1. 11541 X MILTON BUCHLER, Primary Examiner.

T. MAJOR, Assistant Examiner. 

